Doctor of Philosophy (Ph.D.)http://dl.lib.uom.lk/handle/123/123482024-03-28T08:25:13Z2024-03-28T08:25:13ZRABAN - a software implementation process for robotic process automation (RPA) projectsPadmini KVJhttp://dl.lib.uom.lk/handle/123/211772023-10-13T02:33:37Z2022-01-01T00:00:00ZRABAN - a software implementation process for robotic process automation (RPA) projects
Padmini KVJ
Robotic Process Automation (RPA), the next level of business process
automation, provides adaptive and transformative solutions to replace timeconsuming,
non-value-adding,
and
repetitive
human
tasks
in
a
Business
Process
(BP).
RPA
based BP transformation projects differ from typical software development
projects because RPA bots are developed on stable code. It is counterproductive to use
existing software processes in RPA projects. A process template (i.e., software
implementation process and metrics to track the project) is yet to be derived for RPA
projects. The estimated initial RPA project failure rates are 30-50%, and the lack of a
fitting implementation process is attributed as one of the key contributors to failure.
We addressed this gap and derived a novel process for RPA projects named Raban and
metrics to track RPA projects.
Scrum was used to formulate the Raban. Focus group discussions were
conducted with scrum teams and identified 80 challenges. Those analyzed in
Straussian grounded theory are grouped into six categories (i.e., lack of agile mindset,
inconsistency in story estimation, client management issues, lack of adherence to agile
practices, scope change in requirement freeze, and lack of quantitative measurement).
Prioritized 15 burning challenges were classified based on significance, and taxonomy
was developed. Derived steps to estimate RPA use-cases and a framework to achieve
customer satisfaction adopting design thinking practices in agile projects. Moreover,
17 software metrics and three artifacts were derived and validated in five scrum
projects. Raban was derived based on the solutions identified and further fine-tuned
based on the feedback from follow-up interviews with the stakeholders and two
workshops conducted with the other RPA project teams. After that, 14 metrics and two
artifacts were derived for Raban and validated in a RPA project. Moreover, to select
the right candidate BP for RPA transformation, predictive machine learning model was
developed, where the decision made as yes/no on RPA suitability. We used 16 factors
and a two-class decision forest classification model to develop the model.
2022-01-01T00:00:00ZA Deep syntactic parser for the Tamil languageSarveswaran Khttp://dl.lib.uom.lk/handle/123/211762023-10-13T02:33:30Z2022-01-01T00:00:00ZA Deep syntactic parser for the Tamil language
Sarveswaran K
Natural Language Processing (NLP) applications have become integral to human life.
A syntactic parser is a vital linguistic tool that shows syntactic relations between the
words in a sentence. These may then be mapped to a tree, a graph, or a formal structure.
Syntactic parsers are helpful for building other NLP applications. In addition,
they help linguists to understand a language better and perform cross-lingual linguistic
analysis. A syntactic parser that performs a deeper analysis and captures argumentative,
attributive and coordinative relations between the words of a given sentence is
called a deep syntactic parser. Tamil is considered a low-resourced language in terms of
tools, applications, and resources available for others to use and build NLP applications
or carry out linguistic analyses. Not many resources, such as treebanks and annotated
corpora, or linguistic analysis tools such as POS taggers or morphological analysers, are
publicly available for Tamil. Available off-the-shelf language-agnostic syntactic parsers
show comparatively low performance because of the rich morphosyntactic properties of
Tamil. This study elaborates on how I developed the first grammar-driven parser for
Tamil, which uses the Lexical-Functional Grammar formalism, and a state-of-the-art
data-driven parser using the Universal Dependencies framework. I have also proposed
an approach to evaluate a syntactic parser’s syntactical coverage, experimented with
transition-based and graph-based approaches, and for the first time, tried multi-lingual
training to develop a data-driven parser for Tamil. A part of speech tagger, a morphological
analyser cum generator, pre-processing tools, and treebanks are the other tools
and resources I have developed to facilitate the development of the parsers. While all
these tools give the current best score for their respective tasks, these resources are
also available online for others to build upon. Moreover, the study also documents my
contributions toward understanding different linguistic aspects of the Tamil language.
2022-01-01T00:00:00ZImproving the effectiveness of MOOCs to meet the 21st century challengesGamage SDhttp://dl.lib.uom.lk/handle/123/187022024-01-12T05:39:04Z2021-01-01T00:00:00ZImproving the effectiveness of MOOCs to meet the 21st century challenges
Gamage SD
Massive Open Online Courses (MOOCs) are a type of online course
designed using principles of education technology. It enables a massive number
of participants to learn online in any course at any time. This affordance of
scaling and open access to education is considered as the globalized solution for
acquiring 21st century skills. However, unrealistic to the vision, pragmatically,
MOOCs are facing challenges. Mainly the content-driven pedagogical structure
with limited system design implications caused fewer interactions and isolations,
thereby resulted in higher dropouts.
Since MOOCs are introduced recently, the problems faced by participants
or its effectiveness are less understood. Thus, a systematic understanding of
arising problems and solutions to this newly emerged phenomenon is well
needed. In this thesis, I explored MOOCs with a holistic view of understanding
emerging problems with empirical pieces of evidence—whether MOOCs meet
the 21st century skill requirements; what factors are affecting the effectiveness of
a MOOC; how can we improve the effectiveness of MOOCs. By exploring the
above questions, this thesis mainly contributes to 1) provide empirical evidence
of the challenges that MOOCs are facing, 2) solicit a framework to identify the
effectiveness of MOOCs, 3) design a novel peer review mechanism, and 4)
develop the novel system PeerCollab to improve effectiveness of MOOCs.
The research begun with exploratory research methods with active data
collection using MOOC users. The analysis conducted using a combined
approach of qualitative and quantitative methods to understand the challenges
and explore the factors affecting the effectiveness of MOOCs. Initially, surveys
were used to identify whether MOOC platforms are providing necessary 21st
century skills such as collaborative skills, creativity skills, communications
skills, and critical thinking skills. Next, a longitudinal qualitative study was used
to gather MOOC experience using participants over 24 months period of time.
Results of the qualitative study were incorporated to build an instrument to
evaluate MOOCs' effectiveness. The instrument was empirically verified and
validated using 121 MOOC participants.
The initial survey to explore 21st century skills yielded results from 391
MOOC participants across six platforms. Descriptive statistics depicted that
majority of participants reflect the gap in MOOCs to provide 21st century skills.
Next, the qualitative analysis using Grounded Theory (GT) and quantitative
analysis using Factor Analysis (FA) resulted in a detailed10-dimensional
framework to evaluate MOOC effectiveness.
Based on the high ranked dimensions in the framework such as
Technology, Collaborativeness, Interactivity and Assessment, two systems were
designed and developed to demonstrate the improved effectiveness in MOOCs.
First, the “Identified Peer Review” (IPR) system demonstrated how peer identity,
incentive algorithm, and effective communication in peer review enhance the
MOOC's effectiveness. Next, the PeerCollab system demonstrated how social
presence can integrate using theories of communities of practices (CoP) into
MOOCs and thereby improve effectiveness. This system also demonstrated an
articulation of CoP to MOOCs by a novel process named Rapid Communities on
MOOCs (RCoM) design with four phases, viz. Cluster, Orient, Focus, and
iii
Network. Evaluations of the systems demonstrated the challenges and
possibilities of integrating such systems into MOOCs and provided a direction to
build effective interventions.
These systems collectively empower interactions in isolated distributed
individuals and form communities to work collectively bridging the gap to meet
the 21st century skills. The work of this thesis actively contributes to the nuance
of technologies that can be used in society specifically for large scale open and
distributed learning contexts.
2021-01-01T00:00:00ZRouting and control mechanisms for dense mobile adhoc networksSooriyaarachchi, SJhttp://dl.lib.uom.lk/handle/123/158472023-07-05T03:38:16Z2016-09-01T00:00:00ZRouting and control mechanisms for dense mobile adhoc networks
Sooriyaarachchi, SJ
It is not an exaggeration to mention that mobile devices have become ubiquitous and they are used for variety of purposes ranging from personal communication to disaster management and more. These devices are capable of establishing mobile ad hoc networks (MANETs) for multihop communication without the support of infrastructure. This enables more interesting and useful applications of mobile devices, for example for collaborative leaners in large classrooms, shoppers in crowded shopping malls, spectators in sports stadiums, online gamers and more. MANETs have not sufficiently developed to a deployable level yet. Routing in MANETs is a major problem. It is challenging to devise routing protocols for MANETs due to dynamic topology resulting from mobility, limited battery life and impairments inherent in wireless links. Traditional routing approach is to tweak the existing routing protocols that are designed for wired networks. Therefore, it is common to appoint special nodes to perform routing controls and gather global state information such as routing tables. We identify this approach as the fixed-stateful routing paradigm. Fixed stateful routing does not scale with the density of MANETs because the routes will get obsolete quickly due to the dynamic topology causing frequent routing updates. The overhead for these frequent updates will be unacceptable when the MANETs become dense. For example, the control overhead of routing updates in most of the traditional routing protocols are of magnitude O(N) or O(N2), where N is the number of nodes in the network. We name the routing approach that does not require to maintain global network states and does not appoint key nodes for routing and control as mobile-stateless routing paradigm. We propose a novel concept called endcast that leverages message flooding for end to end communication in MANETs in mobile-stateless manner. However, flooding causes heavy amounts of redundant messages, contention and collisions resulting in a situation known as broadcast storm problem. When flooding is utilized for end to end communication, the messages will flood beyond the destination. We call this situation broadcast flood problem. Repetitive rebroadcasting in simple flooding is analogous to biological cell division in the growth of human organs. Chalone mechanism is a regulatory system to control the growth of the organs. In this mechanism, each biological cell secretes a molecule called chalone and the concentration of chalones in the environment increases when the number of cells increases. When the chalone concentration exceeds a threshold the cells stop dividing themselves. Counter based flooding is one of the efficient flooding schemes, in which a node decides not to rebroadcast a received message if the message is subsequently heard multiple times exceeding a predefined threshold during a iv v random wait period. Inspired by the chalone mechanism in the growth of the organs we selected counter based flooding to unicast messages in a MANET. We proposed an inhibition scheme to stop the propagation of message beyond the destination to mitigate the broadcast flood problem. In this scheme, the destination transmits a smaller size control message that we call inhibitor that also propagates using counter based flooding but with a smaller random wait period than in the case of data message. Furthermore, inhibitors are limited to the region of the MANET covered by data flooding. The proposed endcast scheme outperforms simple flooding in such a way that over 45% of redundant messages are saved in all the network configurations starting from 100-node network in ideal wireless conditions when the nodes were placed on a playground of 600m 400m and each node was configured to have 200m of transmission radius. Similarly, the protocol manages to save over 45% of redundant messages for all node densities ranging from 10 to 300 in realistic wireless conditions simulated by IEEE 802.11g standard wireless MAC implementation with power saving transmission radius of 40m. This saving increases rapidly as networks grow by size in both the ideal and realistic wireless network conditions. The inhibition scheme of the protocol was also found to be effective, for example, redundant messages grow in number at a rate about 8 frames per every 25 nodes added to the network when there is inhibition in operation whereas the growth rate is about 170 frames per every 25 nodes when the protocol operates without inhibition in the simulated network scenario. The major contribution of this research is the analytical model that we developed to design and evaluate endcast schemes. We developed a graph theoretic model to evaluate the propagation of messages in endcast, based on a preliminary model developed by Viswanath and Obraczka [2]. We modified the model by (i) improving its method of estimating the number of new nodes reached by each level of rebroadcast (ii) modeling the impact of node mobility and (iii) incorporating time domain representation to model the flooding schemes that involve random assessment delays (iii) enabling it to represent efficient flooding schemes such as counter based flooding. We present the process of estimating the area covered by the propagation of flooding messages using a geometric method. Time domain is represented by indesing the edges of the flooding graph by time. The counter value and the threshold in counter based flooding are converted into a rebroadcasting probability and estimated using a probability mass function that we constructed by considering the overlapping of radio range circles of the nodes.
2016-09-01T00:00:00Z